Arrowrock Reservoir water level: Arrowrock 
75.1 ft low
Arrowrock Reservoir is 75.1 ft below full pool, about normal for early November. The Arrowrock Dam gauge read 3,140.62 ft at 1:00 AM MST, November 4, 2026.
How Arrowrock stands today
In early November Arrowrock normally sits near 3,139.97 ft, 75.8 ft under full pool, so most of today's gap is the usual seasonal drawdown.
- 3,140.62 Feet above sea level1:00 AM MST, November 4, 2026, NGVD29 datum.
- −75.13 Feet from full poolFull pool today is 3,215.75 ft.
- +0.65 Feet from normal for Nov 4Median of 1996–2025 is 3,139.97 ft. Today ranks in the 53rd percentile.
- −3.64 Feet from a year ago3,144.26 ft on November 4, 2025.
- +14.24 Feet over 30 days+4.85 ft over the past 7 days.
The past year, day by day
The shaded band is where Arrowrock usually sits on each date: the middle 80% of years from 1996 to 2025. The blue line is the past 12 months; the sand line is the 12 months before. Hover or use the arrow keys to read any day.
- Past 12 months
- The 12 months before
- Normal range (middle 80% of years)
- Median
- Full pool
Monthly average since 2006
Readings for the last 30 days
| Date | Level (ft) | Normal (ft) |
|---|---|---|
| November 4, 2026 | 3,140.62 | 3,139.97 |
| November 3, 2026 | 3,140.33 | 3,139.38 |
| November 2, 2026 | 3,139.51 | 3,138.84 |
| November 1, 2026 | 3,138.67 | 3,138.29 |
| October 31, 2026 | 3,137.86 | 3,137.73 |
| October 30, 2026 | 3,137.05 | 3,137.15 |
| October 29, 2026 | 3,136.29 | 3,136.57 |
| October 28, 2026 | 3,135.77 | 3,136.00 |
| October 27, 2026 | 3,135.75 | 3,135.52 |
| October 26, 2026 | 3,135.45 | 3,135.02 |
| October 25, 2026 | 3,134.62 | 3,134.46 |
| October 24, 2026 | 3,133.71 | 3,133.89 |
| October 23, 2026 | 3,132.88 | 3,133.28 |
| October 22, 2026 | 3,132.81 | 3,132.63 |
| October 21, 2026 | 3,132.65 | 3,131.96 |
| Date | Level (ft) | Normal (ft) |
|---|---|---|
| October 20, 2026 | 3,132.41 | 3,131.26 |
| October 19, 2026 | 3,131.75 | 3,130.60 |
| October 18, 2026 | 3,130.93 | 3,129.97 |
| October 17, 2026 | 3,130.14 | 3,129.76 |
| October 16, 2026 | 3,129.45 | 3,129.66 |
| October 15, 2026 | 3,129.13 | 3,129.43 |
| October 14, 2026 | 3,128.78 | 3,128.86 |
| October 13, 2026 | 3,128.47 | 3,128.29 |
| October 12, 2026 | 3,128.08 | 3,127.74 |
| October 11, 2026 | 3,127.41 | 3,127.25 |
| October 10, 2026 | 3,126.71 | 3,126.84 |
| October 9, 2026 | 3,126.31 | 3,126.14 |
| October 8, 2026 | 3,126.28 | 3,125.65 |
| October 7, 2026 | 3,126.29 | 3,125.46 |
| October 6, 2026 | 3,126.33 | 3,125.14 |
Is the water above your dock?
Enter the elevation of your dock, ramp end or a mark on your shoreline, in feet above sea level (NGVD29, the datum the Army Corps of Engineers uses for this gauge). You will see how far the water is above or below it today, and how often it dipped below it in each month since 2016.
| Month | Low year (10th %) | Median | High year (90th %) | Days above your mark |
|---|---|---|---|---|
| January | 3,164.70 | 3,180.32 | 3,208.23 | — |
| February | 3,180.75 | 3,197.23 | 3,207.56 | — |
| March | 3,163.76 | 3,199.58 | 3,208.52 | — |
| April | 3,153.82 | 3,195.51 | 3,209.22 | — |
| May | 3,174.27 | 3,195.99 | 3,211.36 | — |
| June | 3,177.51 | 3,205.57 | 3,212.44 | — |
| July | 3,146.07 | 3,176.30 | 3,200.98 | — |
| August | 3,111.19 | 3,124.68 | 3,171.35 | — |
| September | 3,106.28 | 3,126.08 | 3,148.82 | — |
| October | 3,113.24 | 3,132.65 | 3,144.85 | — |
| November | 3,127.08 | 3,149.20 | 3,166.76 | — |
| December | 3,145.80 | 3,166.57 | 3,196.13 | — |
Other Idaho lakes, lowest first
| Lake | Level (ft) | Vs full pool |
|---|---|---|
 Ririe Reservoir | 5,064.87 | 41.1 ft below |
| Dworshak Reservoir | 1,514.51 | 85.5 ft below |
 American Falls Reservoir | 4,319.46 | 35.0 ft below |
 Lake Cascade | 4,815.55 | 12.5 ft below |
| Palisades Reservoir | 5,521.89 | 97.1 ft below |
 Lucky Peak Lake | 2,946.10 | 16.6% full |
| Anderson Ranch Reservoir | 4,150.07 | 43.9 ft below |
 Lake Pend Oreille | 2,053.34 | 9.2 ft below |
| Brownlee Reservoir | 2,060.84 | 13.2 ft below |
Arrowrock questions
What is full pool at Arrowrock Reservoir?
Full pool at Arrowrock Reservoir is 3,215.75 ft above sea level today. The agency's own term for it is “top of normal.”
Is Arrowrock Reservoir full right now?
No. It is 75.1 ft below full pool. In early November Arrowrock normally sits near 3,139.97 ft, 75.8 ft under full pool, so most of today's gap is the usual seasonal drawdown.
Is Arrowrock Reservoir lower than normal for early November?
No, it is close to normal. The median level on Nov 4 across 1996–2025 is 3,139.97 ft, and today's 3,140.62 ft is +0.65 ft from it. In 8 of 10 years the level on this date fell between 3,120.77 and 3,151.60 ft.
How does Arrowrock Reservoir compare with last year?
A year ago, on November 4, 2025, it stood at 3,144.26 ft. It is 3.64 ft lower now.
What are the highest and lowest levels since 1995?
In the daily record we hold, which starts in 1995, the highest daily level was 3,217.16 ft on July 11, 1995 and the lowest was 1,513.19 ft on September 6, 2003.
How often is this page updated?
We pull new readings from the U.S. Army Corps of Engineers several times a day. This page was last rebuilt on Wed, 04 Nov 2026 15:13:17 UTC. Readings are provisional and can be revised by the agency.